Improvement in hoisting-machines



- had to the accompanying drawings, making a ered are placed. said means being composed 4rack-bar, as shown in Figs.2 and 3. On'eaoh UNITED STATES PATENT OFFICE.

IMPROVEMENT IN HoisTlNG-MACHINES.

Specification forming part of Letters Patent No. 42,595, dated May 3, 1864.

.To aZZwhom it may concern:

Beit known that I, F. B. PERKINS, of Roxbury, in the county of Norfolk and State of Massachusetts, have invented a new and Im proved Hoistinglllachine; and I do hereby declare that the t'ollowingis a full, clear, and exact description of the same, reference being part of this specification, in which-.-

Figure lis an elevation of a hoisting-ma chine made according to my invention; Fig. 2, a vertical section ofthe same, taken in the line .fr Fig. l; Fig. 3, a plan or top view of the same.

Similar letters ot' reference indicate corresponding parts in the several Iigures.

This invention relates to a new and imp: oved hoisting-machine, designed for elevating and lowering goods in warehouses, and for other similar or analogous purposes.

The invention consists in the means employed for operai ing the i'llatform'or receptacle on which the goods to be elevated and lowot' racks attached to posts, between which the platform or receptacle works, pinions, wormwheels, and screws, which are combined with the platform and are put iu motion by an endless belt or other suitable means.

To enable those skilled in the art to fully i understand and construct my invention, I will proceed to describe it.

A A representtwo vertical posts, which are firmly secured, at a proper distance apart, in' any proper way; and B B are two racks, which f are attached to the inner sides of the posts l A A. These racks are double ones-that is to say, teeth are cut on the two opposite sides f' of each rack-bar, as shown clearly in Fig. 2. C represents a platform, which is fitted between the two posts A A, and allowed to move freely up and down. This platform has an upright, D, attached to each end` of it. These uprghts are directly opposite the racks B B, and are provided with cross-heads e a', in-which are the bearings of two shafts, EI'E, said bearings being near the ends of the cross heads. 'On the ends of the shaftsE E there are placed pinions F, which gear into the racks B, a pinion being at each side of each shaft E there is fitted a worm-wheel, G, into which screws H H gear. Thesescrews have their threads in reverse positions, one being a right and the other a left thread, and the worm-wheels G have their teeth cut to correspond each with the thread of the screw which gears into it. The screws H are. on a shaft, I, the bearings b of which are in the cross-head a,.and on the shaft I, at about its center, there is placed a pulley, J, around which an endless belt or chain, K, passes, said belt or cha-in also passing over a pulley, L, at the upper part of one of the posts A, and around a pulley, M, which is placed on a shaft, N, at the lower partot one ofthe posts A, as sho'wn in Fig. l.

From the above description itywill be seen that by rotating the shaft N motion will be communicated to the endless belt or chain K, and the screw-shaft l rotated by said belt or chain, which passes entirely around the pulley J. The screws H H and'worm-Wheels G G communicate Inotio'n to the shafts E E and pinicns F, and the latter, in consequence of gearing intothe racks B, raise or lower the platform C, according to the direction in which the shaft N is turned. By this simple arrangement several advantages are obtained First, the platform C will not tall, even when loaded, in case ofthe breaking of the belt or chain K; second, no connecting-gearing is employed, nor any gearing which runs with any great degree of velocity, consequently' much wear and tear and, noise are avoided.

I do not claim separately any ot' the parts herein shown anddescribed,v irrespective of their 'combinaticf and arrangement for the purpose specified.

l claim, therefore, as new and desire to sc-.

cure by Letters Patent- I The employment, in a hoisting-machine, of

racks and pinionshaving` teeth of the char-y acter shown in the drawings, and which gear 'with each other, in combination with a platform and with worm screws and worm-wheels,l

or their equivalents, the mechanism being actuated by an endless belt or chain, or by other equivalent means of imparting motion, and

y being constructed and operating substantially Y as described. y

F. B. PERKINS.-

Witnesses:

Taos.. S. J. DOUGLAS, GEO. W. REED.' l 

